Patent Application
20170225918
The present invention is directed to systems and methods for detecting a leading edge of a paper sheet in a paper handling system of a document reproduction device.
It is important, for a variety of reasons, to be able to detect a leading edge of a paper sheet as it travels along the paper part in a document reproduction system. Paper detection sensors are often used throughout the paper path. Reflective-type optical sensors are typically used but these often have problems related to false detection due, for example, to a variability in the reflected signal caused by components, parts and reflections situated in the proximity of the sensor beam. Moreover, these reflective-type optical sensors can also be vulnerable to contamination from paper dust due to the close proximity to each other. In some cases variation in printed image can cause false triggering.
Accordingly, what is needed in this art are systems for detecting a leading edge of a paper sheet in a paper handling system of a document reproduction device.
What is disclosed is a system and method for detecting a leading edge of a paper sheet in a paper handling system of a document reproduction device. One embodiment of the present system comprises a light transmissive medium having an outer layer with a lower refractive index and an inner layer with a higher refractive index such that light propagates through the medium and exits an opposite end thereof. An illuminator continuously projects light into a first end of the light transmissive medium. The first end is offset from the illuminator by a first distance to form a first gap. A detector continuously detects the projected light exiting the opposite end of the light transmissive medium which is offset from the detector by a second distance to form a second gap. A sheet being transported by the paper handling system of the document reproduction device traverses an area defined by the first and second gaps which, in turn, causes a signal to be generated indicted that a leading edge of the sheet has been detected. The embodiments disclosed herein provide less sensitivity to reflections from components with a greater degree of robustness to contamination.
Features and advantages of the above-described system and method will become readily apparent from the following detailed description and accompanying drawings.
The foregoing and other features and advantages of the subject matter disclosed herein will be made apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
What is disclosed is a system and method for detecting a leading edge of a paper sheet in a paper handling system of a document reproduction device.
An “illuminator” projects light into a first end of a light transmissive medium. A wavelength of the projected beam of light can be visible or infrared. The projected light traverses the light transmissive medium and exits an opposite end thereof. One or more lens may be fitted between the illuminator and the first end of the light transmissive medium to focus the projected light, as needed.
A “light transmissive medium” enables the passage of light therethrough. In general, the light transmissive medium has an outer layer with a lower refractive index and an inner layer with a higher refractive index such that light propagates through the medium. The medium may be, for example, a highly polished hollow metal tube with a high internal reflectance. The light transmissive medium may be a laminate, a silica-glass, an acrylic, a light transmissive plastic or polymer, a crystal, or a fiber optic material as is known in the arts. In one embodiment, the light transmissive medium is tubular with a longitudinal axis that is substantially arcuate. The light transmissive medium may have one or more first ends and one or more opposite ends. The projected light enters the light transmissive medium at the first end and exits at the opposite (second) end.
A “photodetector” or simply “detector” refers to one or more light sensing elements which are sensitive to a wavelength of the light projected by the illuminator. The detector continuously senses the light exiting the light transmissive medium. When the detector no longer senses the light, a signal is generated. Alternatively, the detector continuously generates a signal until light is no longer detected. The photodetector may be the signal generator. One or more lens may be fitted between the second end of the light transmissive medium and the detector to focus the light, as needed.
A “first gap” is formed between the illuminator and the first end of the light transmissive medium. The paper being transported through the document reproduction device by the paper handling system moves the paper such that it traverse the area defined by the first gap.
A “second gap” is formed to an area between second (opposite) end of the light transmissive medium and the detector. The paper being transported through the document reproduction device by the paper handling system moves the paper such that it traverse the area defined by the second gap. The first and second gaps may be the same distance.
A “paper handling system”, as is generally understood in the document reproduction arts, transports a sheet of paper from the paper tray, to a location where the print engine can mark the sheet, and out to an output tray for collection by a user. The illuminator and detector are positioned on the same side of the paper path along which the sheet travels, with the light transmissive medium being on an opposite side of the paper path.
It should be appreciated that the steps of “detecting”, “projecting”, “transporting”, “signaling”, and the like, as used herein, may be facilitated by a microprocessor executing machine readable program instructions retrieved from a storage device.
Reference is now being made to
Reference is now being made to
At step 302, project, by an illuminator, light into a first end of a light transmissive medium. The projected light propagates through the medium and exits an opposite end thereof. The first end is offset from the illuminator by a first distance to form a first gap.
At step 304, detect, by a detector, the projected light exiting the opposite end of the light transmissive medium. The opposite end of the light transmissive medium is offset from the detector by a second distance to form a second gap. One embodiment of the present system showing the first and second gaps is shown and discussed with respect to
At step 306, transport, by a paper handling system, a sheet along a paper path of a document reproduction device. The transported sheet traverses the area defined by the first and second gaps. One embodiment of the leading edge of a transported paper sheet shown traversing the area defined by the first and second gaps is shown and discussed with respect to
At step 308, a determination is made whether the detector no longer detects the light exiting the opposite end of the light transmissive medium. If so then, at step 310, signal that a leading edge of the sheet has been detected. In this embodiment, after the transported sheet has passed, processing repeats with respect to step 304 wherein the detector continuously detects the light exiting the opposite end of the light transmissive medium until the next sheet being transported by the paper handling system interrupts the detector detecting the projected light. A next signal is sent that a leading edge of the next paper sheet has been detected. Processing repeats in a similar manner for each successive paper sheet being transported by the paper handling system of the document reproduction device. Processing ends when a user uses the user interface of the document reproduction device to turn the present system OFF.
The signal generated hereby can be used by any of a variety of sensors within the document reproduction sheet as are needed, depending on the system design, and therefore a discussion as to what is being done with any the signal by any particular device or controller of the document reproduction system is omitted as being beyond the scope of the present invention.
It should be appreciated that the flow diagrams depicted herein are illustrative. One or more of the operations illustrated in the flow diagrams may be performed in a differing order. Other operations may be added, modified, enhanced, or consolidated. Variations thereof are intended to fall within the scope of the appended claims.
The teachings hereof can be implemented in hardware or software using any known or later developed systems, structures, devices, and/or software by those skilled in the applicable art without undue experimentation from the functional description provided herein with a general knowledge of the relevant arts.
One or more aspects of the system and methods described herein are intended to be incorporated in an article of manufacture which may be shipped, sold, leased, or otherwise provided separately either alone or as part of a product suite or a service.
It will be appreciated that the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into other different systems or applications. Presently unforeseen or unanticipated alternatives, modifications, variations, or improvements may become apparent and/or subsequently made by those skilled in this art which are also intended to be encompassed by the following claims.
